E-Tile Transceiver PHY User Guide

ID 683723
Date 7/08/2024
Document Table of Contents RX Adaptation Modes

The E-tile supports the initial and continuous adaptation modes.
Table 41.  E-Tile Receiver PMA RX Adaptation Modes
Mode Description
Initial adaptation During initial adaptation, the adaptation engine adapts all of the RX analog front end (AFE) parameters to optimize the receiver eye opening and adjusts the vertical and horizontal sampling location accordingly.
  • This mode calibrates the PMA to known good settings.
  • It is disruptive tuning and impacts the data traffic.

Run initial adaptation under either of the following conditions:

  • On device configuration. Refer to PMA Bring Up Flow for more detail.
  • When there is change in the physical channel between TX and RX.
  • During debug, when you switch back and forth between internal serial loopback and mission mode and the BER readout is exceptionally high, Intel recommends that you issue a PMA reset followed by loopback mode and initial adaptation.
Continuous adaptation The goal of this adaptation is to maintain the signal quality at the sampler close to the initial adaptation over time and temperature.
  • This mode is run only after running initial adaptation during PMA bring up.
  • This mode tracks the temperature over time by continuously adapting new values of the RX AFE parameters.
  • This mode is a continuous and non-disruptive process, that is, it does not impact the data traffic.
  • During a link debug process with the hard PRBS generator and verifier, you cannot read out accumulated errors from the error counter unless you stop continuous adaptation. Details on PMA code and value to stop continuous adaptation are available in the PMA Register Map.

For more details on Register Read/Write support and programming, refer to PMA Receiver Equalization Adaptation Usage Model and 0x000A: Receiver Tuning Controls to configure these parameters.

Table 42.  PMA Parameter Description and RangeThis table lists all PMA parameters that can be optimized either manually or by the adaptation tuning engine. Some of these parameters are tuned by the adaptation tuning engine during initial adaptation and continuous adaptation as shown below. You can also manually specify some of these parameters. To avoid getting your manually optimized parameter overwritten by the adaptation tuning engine, you must fix the parameter. Refer to PMA Avalon® Memory-Mapped Interface Registers and PMA Receiver Equalization Adaptation Usage Model to understand how the parameter can be fixed such that it is not overwritten by the adaptation engine.
Parameter Min Max Initial Adaptation Continuous Adaptation Manual Optimization Possible Firmware Default
GainLF 0 15 Yes Yes Yes 8
CTLE LF Min 0 15 N/A N/A Yes 0
CTLE LF Max 0 15 N/A N/A Yes 15
GainHF 0 15 Yes Yes Yes 0
CTLE HF min 0 15 N/A N/A Yes 0
CTLE HF max 0 15 N/A N/A Yes 15
GS1 0 3 No No Yes 0
GS2 0 3 No No Yes 0
RF_P2 -10 15 10 Yes No No 0
RF_P2_MIN -1015 10 N/A N/A Yes -10
RF_P2_MAX -1015 10 N/A N/A Yes 10
RF_P1 0 15 Yes Yes No 0
RF_P1_MIN 0 15 N/A N/A Yes 0
RF_P1_MAX 0 15 N/A N/A Yes 15
RF_P0 -1515 15 Yes Yes No 0
RF_B1 0 8 Yes Yes Yes 0
RF_B0 0 5 Yes Yes Yes 0
RF_B0T 0 50 No No Yes 0
RF_A - NRZ 100 160 No No Yes 160 16
RF_A - PAM4 100 160 No No Yes 130 17

PMA Initial Adaptation Effort Status

  • 0 = Low Effort (00_effort) is for NRZ Ethernet AN/LT and CPRI protocols only and is the quickest to complete. This meets the 500 ms compliance time for Ethernet and 100 ms compliance time for CPRI.
  • 1 = Medium Effort (05_effort) is for the PAM4 Ethernet AN/LT protocol only, to meet the IEEE link-up time of 3 seconds.
  • 2 = Full Effort (10_effort) is for general usage (NRZ and PAM4), to provide the best performance and stability, but takes the most time to complete compared to other initial adaptation efforts. This is the recommended adaptation mode.

See the "Loading PMA Configuration Register START_ADAPTATION" figure.

You can set the initial adaptation effort using attributes directly. See Initial Adaptation Effort Levels for information on the attributes to send.

15 Two’s complement, 16-bits
16 The power-on default is 0. This updates to 160 after running medium or full effort initial adaptation with internal serial loopback disabled. Low effort initial adaptation keeps RF_A at 0.
17 The power-on default is 0. This updates to 130 after running medium or full effort initial adaptation with internal serial loopback disabled.